Dark matter is even more mysterious than we thought, according to new research.
The elusive matter makes up far more of the universe than the stuff we see around us. But it still remains almost entirely mysterious: we only know it exists through its interactions with the visible universe, and know very little about it.
Scientists have now revealed that a previous breakthrough – which at the time appeared that it could cast some light on dark matter – might actually have been wrong. Three years ago researchers were excited to find that a galaxy in a cluster of galaxies appeared to have become separated from the dark matter that surrounded it.